有限元及刚柔联合仿真在曲轴设计中的应用

The supply of the finite element method and rigid-flexible body co-simulation in crankshaft designing

曲轴属于高速旋转部件,其运动过程是内燃机产生振动的一个主要原因,受力是典型的交变应力,某些部位交变应力会达到很高的数值,容易产生疲劳破坏。如果在仿真过程中只考虑曲轴模型各构件为刚体的情况,则不能精确地模拟曲轴的工作情况;利用虚拟样机技术、柔性体理论及模态分析技术,联合运用Pro/E、有限元分析软件MSC.PATRAN/NASTRAN及机械系统动力学仿真软件MSC.ADAMS,考虑曲轴的变形,在NASTRAN中生成曲轴的模态中性文件,在MSC.ADAMS中用模态中性文件替换刚性曲轴进行动力学仿真,得到曲轴的应力和位移等动力响应,为曲轴的动态疲劳分析提供依据,为曲轴设计提供参考。

Crankshaft belonging to the high speed rotation component, the motion of the crankshaft is one of the main reason engine vibration, and the stress is the typical alternate stresses. Certain spot alternate stresses will achieve the very high value, easy to have the fatigue failure. If only considers each component of the crankshaft model for the rigid body in the simulation process situation, then cannot precise simulation the crankshaft＇s working condition. Based on the Virtual Prototype Technology , Flexible Body Theory and the Modal Analysis Technology, combined with Pro/E and the Finite Element Analysis software MSC.PATRAN/NASTRAN, mechanism system simulation software MSC.ADAMS. Considered the deformation of the crankshaft, the Modal Neutral File of the crankshaft will be created in NASTRAN, using the Modal Neutral File replacing the rigid crankshaft processes the Dynamic Simulation, the dynamic response of crankshaft stress and displacement and so on is analyzed by Dynamic Simulation in MSC.ADAMS, and the consequence results can be referenced for design and dynamic fatigue analysis of crankshaft.